Hezbollah’s leader delivered a defiant speech Tuesday that sought to dispel any notion that his Lebanese Shiite group is strained by its intervention in Syria, warning that it could still confront Sunni extremists and Israel.

In a televised address marking the annual Shiite Ashura observance, Hasan Nasrallah defended the decision about two years ago to deploy thousands of Hezbollah fighters to bolster the regime of Syrian President Bashar al-Assad.

Nasrallah described Hezbollah’s role in the three-year-old Syrian civil war as “a great victory,” but the intervention has angered many in the Arab world, especially Lebanon’s Sunnis, who support Assad’s largely Sunni opponents.

Hezbollah’s forces have suffered hundreds of battlefield deaths in Syria, but Nasrallah, speaking to Shiite worshipers in Lebanon and audiences across the region, said the group is “stronger than before” and has gained serious wartime “experience.”

“The whole world was in agreement” that the Syrian government would fall “within months,” he said. “However, nearly four years have passed, and Damascus is still firm.”

He also warned that Hezbollah could still deal devastating blows to longtime foe Israel. Israel and Hezbollah fought a 34-day war in 2006 that destroyed swaths of Lebanon.

Nasrallah warned Israelis to “close your airports, your ports” if fighting should erupt, because all of Israel is within range of Hezbollah rockets.

The remarks came amid heightened tension in Lebanon stemming partly from Hezbollah’s presence in Syria, which critics say has worsened sectarian relations in Lebanon.